Safety Goggles with Elastic Headband to Improve N95 Fit Following Failed Quantitative Fit Test

Abstract

Introduction: N95 respirators, together with eye protection, form vital elements of personal protective equipment (PPE) for healthcare workers (HCW) caring for patients with respiratory infections, such as COVID-19. Duckbill N95 respirators are widely used but have a high failure rate when Fit Tested. The commonest site for inward leaks is the region between the nose and maxilla. Safety goggles with an elastic headband may press the upper rim of the respirator against the face, thereby reducing inward leaks. We hypothesized that the use of safety goggles with an elastic headband will improve the overall fit-factor of a duckbill N95 respirator and increase the proportion of users who pass a quantitative Fit Test.

Methods: About 60 volunteer HCWs, who had previously failed quantitative Fit Testing with a duckbill N95 respirator, participated in this before-and-after intervention study. A PortaCount® 8048 was used for quantitative Fit Testing. The test was first performed with a duckbill N95 respirator only. It was then repeated after participants donned a pair of safety goggles (3M Fahrenheit, ID 70071531621).

Results: Before the intervention, i.e., with the respirator only, 8 (13.3%) participants passed their Fit Test. This increased to 49 (81.7%) after the application of safety goggles (OR 42, 95% CI 7.14-1697.9, p < 0.0001). The adjusted mean overall fit factor, using Tobit regression analysis, increased from 40.3 to 193.0 (t = 12.32, p < 0.001).

Conclusion: The use of safety goggles with an elastic headband significantly increases the proportion of users who pass a quantitative Fit Test and improves the fit-factor of a duckbill N95 respirator.

How to cite this article: Kamal M, Bhatti M, Stewart WC, Johns M, Collins D, Shehabi Y, et al. Safety Goggles with Elastic Headband to Improve N95 Fit Following Failed Quantitative Fit Test. Indian J Crit Care Med 2023;27(6):386-391.

Keywords: COVID-19; Eye protection; Fit Test; Goggles; N95 respirators; Personal protective equipment.

Fig. 1

PortaCount Respirator Fit Tester 8048 | TSI

Fig. 2

Proshield® duckbill N95 respirator | BSN Medical

Fig. 3

(A) Demonstrates the common site of inward leak for an N95 respirator; (B) Shows the modified N95 respirator and safety goggles pressing the gap between the nose and the cheeks

Fig. 4

Fahrenheit antifog safety goggles | 3M

Fig. 5

Testing sequence

Fig. 6

Tube connecting PortaCount® to participant's respirator

Equation 1

The formula used to calculate the overall fit-factor. Fit-factor is represented as “ff” in the equation

Fig. 7

Adjusted mean overall fit-factor calculated using Tobit regression analysis. The horizonal dashed line represents the pass/fail threshold

Fig. 8

Proportion of participants who passed (ff ≥ 100) and failed (ff < 100) the overall Fit Test before and after the use of the safety goggle